So i've been throwing a few various codes, 171 and 174's mostly. Car has 245k on it.

Been going through about 1 qt of oil every 500 - 700 miles. which for me is weekly. Had my brother driving by me one day and he said under acceleration, especially heavy accel, that a black grey smoke comes out.

Of course two local mechanics tell me 1. replace engine 2. valve seals. BMW dealer says with this M54 engine he's yet to see bad seals, thinks it's the CCV valve ($1k job uhh nah DIY).

So what does the hive think? My engine isn't spotless mind you, but i also have no drips on floor, the under cover or anything anywhere on engine explaining the 1 qt usage.

VCG isn't leaking. So i don't mind doing the CCV but if i do, i'm going to go in from the front and just hit the OFH gasket since that's a MUCH easier path to hit this chnage out (I did it by the book from the right side (DISA area) about 2-3 yrs ago...shortly after my OFH gasket went and i was like dayum...this would have been much easier this way!)

as for the smoking...mind you I rarely see it in the mirror, when i have its been under heavy acceleration TRYING to see if i see smoke. At idle I don't see anything when i exit the car, though it does smell oily.

If i do this again i'm doing CCV, OFH, injectors (refurbs), new coils/plugs.

Thanks for the hive responses.